Called my mobile phone.

Text my cell with message - "Shoppers Wanted! Get up to $100/day by shopping! Call 18665711026 now.

Received text message on my Tracfone- Attn: You've been selected to receive a $200 Gas Voucher & Discounts to your fave stores! Call 1801-618-1237 to claim.

3rd time I've gotten unwanted text messages since signing up for free samples on eBay's new eBay eXtras page which allows you to get free samples & coupons from major manufacturer's.

Received a spam text from this number, offering me "up to $5,000 in Cash!" I swear I get more spam texts than real ones lately.

THIS IS A SCAM. This is a version of the advance-fee-for-something scam where something is a grant, loan, lottery winnings, interest rate reduction, tax reduction, gift card, refund, doggie, cruise, vacation, free gas, etc., and the advance-fee is for tax, shipping, registration, insurance, secure handling, processing, etc. They may send you a fake check, may want your credit/debit card or bank account number,  or tell you to wire cash via Western Union, Moneygram, etc. They can put recurrent difficult-to-cancel monthly charges or a 1-time charge on your card or bank account, and sell account info to other criminals and you'll have to replace accounts altogether. Wired-cash is irretrievable - once it's picked up at the other end, it's untraceable and gone. If they want you to call them up for instructions, they may tell you not to discuss the wire with Western Union desk clerks but the real reason is WU clerks are familiar with these scams and will warn you not to wire the money. Report to US Postal Service Inspectors https://postalinspectors.uspis.gov/forms/MailFraudComplaint.aspx , the Federal Communications Commission http://esupport.fcc.gov/complaints.htm , the Federal Trade Commission https://www.ftccomplaintassistant.gov/ and your state AG, as appropriate.