You are not always going to see either sticker on an anime figure product. And not having one DOESN'T mean it's not genuine. BUT, if you do see the sticker, chances are excellent that the product in question is legitimate (unless, of course, the bootleggers start creating their own counterfeit stickers for these distributors; but this hasn't happened yet to my knowledge).
A related but trickier factor is the companies involved. It's related to the sticker factor precisely because SOME manufacturers, studios (as in the studio that produced the anime show), and publishers (as in the Japanese manga publisher) slap on their own stickers to declare a product's authenticity. And you the consumer have to be educated (by reading this article) to know WHICH companies engage in this practice. The granddaddy of all companies that engage in this practice is Gainax, the folks who brought you Evangelion and gives its blessing to the flood of Eva related products in the markets every year. By now, you're probably familiar with Gainax' sticker---a tiny silver sticker or hologram with "GAINAX" written across, and "OFFICIAL LICENSED" right below. The related/affiliated anime figure manufacturers Alter Co., Ltd., Good Smile Company, and Max Factory emphasize the spirit of hobby Japan on their sticker with a huge "H" with swirl around this letter in the hologram sticker, and a smaller "JAPAN" inserted over the H. The hottest company in the Japanese gaming scene, TYPE-MOON also engages in this practice by using a hologram sticker with an italicized "Tm" in the center, "TYPEMOON" in the background, and some Japanese characters below the Tm. Japanese animation studio Studio Pierrot uses a square sticker with the face of a clown in a circle, with "PIERROT" below the face and inside circle. Japanese manga publisher Kodansha uses a rectangular sticker with "KODANSHA" in bold and repeated vertically within the sticker. Please study the sample stickers below carefully. [Please note that the NAF watermarks in these images were inserted ubiquitously to prevent bootleggers from taking these images and passing them off as images from their counterfeit products.]
These stickers are EXTREMELY helpful in determining whether a product is licensed, and whether the anime figure in question is a counterfeit. However, please note that there are many, many more stickers than what we've shown here. And manufacturers will continue to create new stickers and to utilize other methods to authenticate their licensed goods, and to deter bootleggers.
The final two factors (quality and price) are also considerations. But they're not very helpful if the consumer is making an online purchase through an auction site like ebay, where many counterfeit and bootleg anime figure products are sold. One reason is that when you buy an item online, you simply don't have an opportunity to examine the product physically to evaluate its quality. And if the seller sets a low starting price for the auction, the winning bid may end up low if there are few bidders for that auction.